Means for securing crank-arms to shafts.



no. 635,766. Patented Ont. 3|, I899.

J. BILLET.

MEANS FOR SECURING CRANK ARMS T0 SHAFTS.

(Application filed Mar. 27, 1899) (No Model.)

ITEB STATES ATEN rrtca JOSEPH GILLET, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE MIL- WAUKEE MANUFACTURING COMPANY, OF SAME PLACE.

MEANS FOR SECURING CRANK-ARMS TO SHAFTS.

SPECIFICATION forming part of Letters Patent No. 635,766, dated October 31, 1899.

Serial No. 710,644. (No model.)

To all whom it may concern.-

Be it known that I, JOSEPH GILLET, of Milwaukee, in the county of Milwaukee and State of IVisconsin, haveinvented a new and useful Improvement in Means for Securing Crank- Arms to Shafts, of which the following is a description, reference being had to the accom panying drawings, which are a part of this specification.

The object of my invention is to provide means for securing a crank-arm to a shaft detachably, the invention having special reference to securing a tight and accurate fit of the shaft in the arm, in so securing the arm on the shaft that it cannot escape or be accidentally pushed off from the shaft, that the arm will be secured to the shaft so as to rotate therewith, and that the key or securing device will be held in position except against actual force applied directly thereto to remove it from its seat.

My invention is especially adapted for use in connection with a bicycle-shaft and its pedal crank-arm, and the drawings are intended to illustrate my device in connection with fragments of a bicycle-shaft and pedal crank-arm, showing the relation of the invention thereto and combination therewith.

In the drawings, Figure 1 shows a fragment of a bicycle-shaft and pedal crank-arm thereon secured thereto by means of my improved construction. Fig. 2 is an end view of the shaft with the crank arm thereon secured thereto in my improved manner. Fig. 3 is a side View of the shaft with the crank thereon secured thereto in my improved manner. Fig. 4 is a central transverse section of the shaft and related devices.

In the drawings, A is a fragment of a bicyole-shaft.

Bis a fragment of a pedal crank-arm on the shaft and secured detachably thereto by the key 0.

The shaft A is slitted centrally transversely at its end, as shown at D, and is provided with a key-recess in its end, transversely thereof, which recess extends across the end of the shaft in the plane of the slit D and on both sides thereof. The pedal-arm B is provided with a key-recess corresponding with the keyrecess in the shaft A and adapted to register therewith when the arm is fitted on the end of the shaft. The key-recess in the arm B and in the end of the shaftA is of such form and size as adapts it to receive snuglybut releasably therein the key 0. The side walls F F of the key C (which side walls when the key is in its seat in the arm and in the shaft are presented laterally with reference to the shaft A) are beveled or so inclined that the inner face or bottom of the key 0 is wider than its outer or exposed face, or, in other words, the key 0 is dovetailed in cross-section. The arm B is so constructed with reference to the shaft A that when it is placed on the end of the shaft its outer surface is flush with the end of the shaft, and the key 0 is preferably so constructed that when it is placed in its seat in the recess therefor in the shaft and in the crank-arm its outer surface is flush with the end of the shaft and with the corresponding surface of the crank-arm. The key C and its recess is also tapered, narrowing inwardly from the outer end of the recess to and across the shaft and in the arm beyond the shaft, whereby the key is adapted to be forced into the shaft, spreading its adjacent parts on opposite sides of the slit-D apart and against the wall of the aperture in the arm B, thus fitting the shaft tightly in the arm B. As this key extends not only entirely across the shaft S, in the end thereof, but also along in the arm B adjacent to the shaft, the shaft is held to rotation with the pedal crank-arm. By reason of the beveled sides F F of the key and of its tapering form the key is adapted when forced into the recess therefor in the arm and in the registering recess in the shaft to lock the crank member to the shaft securely, so as to compel concurrent rotation and at the same time to so spread the parts of the shaft from each other as to fit them tightly against the arm and by reason of the bevel of the key to hold the key securely in its seat and the pedal crank member firmly to the shaft.

. The key-recess in the arm B is continued inwardly to some distance beyond the-normal inner end of the key, as shown at E in Fig. 2 and as indicated by dotted lines in Fig.- 1, and the bottom of the recess is preferably inclined outwardly, so that the recess terminates at a distance from the key when in its seat. This open space formed by the continuation of the recess inwardly is adapted for the insertion therein of a tool against the inner end of the key, whereby the key may be driven out of its seat endwise when it is desired to take the crank-arm off from the shaft.

WVhat I claim as my invention is- 1. The combination with a shaft slitted transversely at its end and provided with a transverse key-recess in the plane of the slit and across the end of the shaft, of a crankarm on the end of the shaft having a recess in its outer surface registering with the recess in the shaft, and a key fitted in the shaft and crank-arm recesses, the key and the recesses being of tapered form longitudinally and beveled and dovetail form in cross-section, the key being adapted to spread the slitted end of the shaft.

2. The combination with a shaft provided 1 with a transverse slit and key-recess, of a crank-arm fitted on the shaft and provided ally fitted and inserted in the correspondinglyshaped recesses in the arm and the shaft, the key being adapted by being forced into its seat to spread the members of the shaft and fit them snugly into the shaft-aperture in the crank-arm, the recess in the crank-arm being continued inwardly from the end of the key and beveled outwardly for receiving a detaching-tool therein.

In testimony whereof I aifix my signature in presence of two witnesses.

JOSEPH GXLLET. W'itnesses:

A. L. MoRsELL, (3. T. BENEDICT; 

